Rework IR code generation for try/catch/finally

Simplify the generated code. Add a special block to catch
exceptions thrown inside a catch() statement.

store the exception on the stack when entering finally and
rethrow it at the end. This ensure correct behavior for
break/continue/return statements inside finally.

Don't check for exceptions after calling push_catch_scope
and pop_scope in the JIT'ed code. This can lead to infinite
loops when throwing inside an exception handler.

Change-Id: I67e9325794e2fd25b0773b21e02fbaadb43faab0

Change-Id: Ic1ea9c0c43eec1d49177dc1ab4552a1da04e96fe
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/qml/compiler/qv4isel_masm.cpp b/src/qml/compiler/qv4isel_masm.cpp
index 6fe0f27ec3..2d13b4d8c8 100644
--- a/src/qml/compiler/qv4isel_masm.cpp
+++ b/src/qml/compiler/qv4isel_masm.cpp
@@ -818,9 +818,8 @@ void InstructionSelection::callBuiltinDeleteValue(V4IR::Temp *result)
 
 void InstructionSelection::callBuiltinThrow(V4IR::Expr *arg)
 {
-    generateFunctionCall(Assembler::Void, __qmljs_throw, Assembler::ContextRegister,
+    generateFunctionCall(Assembler::ReturnValueRegister, __qmljs_throw, Assembler::ContextRegister,
                          Assembler::PointerToValue(arg));
-    _as->jumpToExceptionHandler();
 }
 
 void InstructionSelection::callBuiltinReThrow()
@@ -828,10 +827,16 @@ void InstructionSelection::callBuiltinReThrow()
     _as->jumpToExceptionHandler();
 }
 
+void InstructionSelection::callBuiltinUnwindException(V4IR::Temp *result)
+{
+    generateFunctionCall(result, __qmljs_builtin_unwind_exception, Assembler::ContextRegister);
+
+}
+
 void InstructionSelection::callBuiltinPushCatchScope(const QString &exceptionName)
 {
     Assembler::Pointer s = _as->loadStringAddress(Assembler::ScratchRegister, exceptionName);
-    generateFunctionCall(Assembler::ContextRegister, __qmljs_builtin_push_catch_scope, s, Assembler::ContextRegister);
+    generateFunctionCall(Assembler::ContextRegister, __qmljs_builtin_push_catch_scope, Assembler::ContextRegister, s);
 }
 
 void InstructionSelection::callBuiltinForeachIteratorObject(V4IR::Temp *arg, V4IR::Temp *result)